You can use your iPhone as a hotspot if that is what you mean - read this.
From Apple's website http://www.apple.com/ios/
On the road, in an airport, at the park — now you can bring Wi-Fi with you wherever you go. Download iOS 4.3 on your iPhone 4, and the next time you find yourself without access to Wi-Fi but in 3G territory, enable Personal Hotspot and share your cellular data connection with your Mac, PC, iPad, or other Wi-Fi-capable device. You can share your connection with up to five devices at once over Wi-Fi, Bluetooth, and USB — with up to three of those connections using Wi-Fi.4 Every connection is password protected and secure. And it’s power friendly, too. iPhone detects when your Personal Hotspot is no longer in use and turns it off to save battery life.
Message was edited by: Demo